The present invention generally relates to methods and apparatus for characterization of polymer samples in liquid chromatography systems, and specifically, for characterization of polymer samples in multi-dimensional liquid chromatography systems. The invention particularly relates, in a preferred embodiment, to characterization of polymer samples in a comprehensive, directly-coupled, multi-dimensional high-performance liquid chromatography systems including a first HPLC dimension adapted for determining composition (e.g., adapted for reverse phase chromatography, adsorption chromatography, and the like such as mobile phase gradient-elution chromatography) and a second HPLC dimension adapted for determining molecular weight or size (e.g., adapted for size exclusion chromatography such as gel permeation chromatography).
Multi-dimensional high-performance liquid chromatography systems are known in the art. See e.g., Murphy et al., Effect of Sampling Rate on Resolution in Comprehensive Two-Dimensional Liquid Chromatography, Anal. Chem. 70, 1585-1594 (1998); Murphy et al., One- and Two-Dimensional Chromatographic Analysis of Alcohol Ethoxylates, Anal. Chem. 70, 4353-4360 (1998); Kilz et al., Two Dimensional Chromatography for the Deformulation of Complex Copolymers, Chapter 17, pp. 223-241 of the text entitled “Chromatographic Characterization of Polymers, Hyphenated and Multidimensional Techniques”, edited by Provder et al. (American Chemical Society, Advances in Chemistry Series 247, 1995); Opiteck et al., Two-Dimensional SEC/RPLC Coupled to Mass Spectrometry for the Analysis of Peptides, Anal. Chem. 69, 2283-2291 (1997); and Trathnigg et al., Two-Dimensional Liquid Chromatography of Functional Polyethers, Chapter 13, pp.190-199 of the text entitled “Chromatography of Polymers, Hyphenated and Multidimensional Techniques”, edited by Provder et al. (American Chemical Society, Symposium Series 731, 1999), each of which is hereby incorporated by reference for all purposes.
Although the methods and systems disclosed to date in the art have proven to be useful for characterizing biological and non-biological polymer samples, they generally suffer from inefficiencies with respect to overall sample throughput, and/or with respect to complicated control and/or operation schemes and systems.
Accordingly, there remains a need in the art for improved methods and systems for effecting multi-dimensional liquid chromatography for characterization of polymer samples.